How To Determine Granule Size

01、 ORACLE_BASIC_How To Determine Granule Size

How To DetermineGranule Size (Doc ID 947152.1)

1. How is the granulesize determined

The granule size isdetermined based on the amount of memory requested at the instance startup. Itis based on the SGA_MAX_SIZE.  IfMEMORY_MAX_TARGET is specified, then SGA_MAX_SIZE defaults to MEMORY_MAX_TARGETfor the purpose of sizing the granule. Once set, the granule size does not change for the life of the instance.

The granule sizes atthe time of writing, are:

RDBMS	SGA_MAX_SIZE  (or memory_max_target)	GRANULE  SIZE
9.2	<=  128MB	4MB
	>  128MB	16MB
10.2	<=  1GB	4MB
	>  1GB	16MB
11gR1	<=  1GB	4MB
	>1Gb  <= 4GB	16MB
	>4Gb  <= 16GB	64MB
	>16Gb  <= 64GB	256MB
	>  64GB	512MB
11gR2  (and 11gR1 with patch 8813366 applied *)	<= 1Gb	4Mb
	>1Gb  <= 8Gb	16Mb
	>8Gb  <= 16Gb	32Mb
	>16Gb  <= 32Gb	64Mb
	>32Gb  <= 64Gb	128Mb
	>64Gb  <= 128Gb	256Mb
	>  128Gb	512Mb

 

2. How to find theGranule size

You can check thegranule size that is currently set for your database instance by running thefollowing SQL statement as SYSDBA

-- You can determineyour granule size with this SQL

SQL> select bytesfrom v$sgainfo where name like 'Granule Size';

There is a 16MB granulesize maximum on 32-bit platforms. This applies even if the granule size is manuallyoverridden.